• Optical combi cryostat

Sample in vacuum

The optCRYO107vac is a combi cryostat with a sample in vacuum or inert gas atmosphere. Cooling agent is placed in a reservoir inside the cryostat body and is flowing into the volume around the sample room through the capillary to cool the heat exchanger. The optCRYO107vac is a cryostat for the temperature region from 2 to 273 K. The sample is attached to the bottom insiide the vacuum chamber that is in the contact with the heat exchanger. The sample temperature is stabilized by resistive heater power on the heat exchanger and the gas flow rate regulation. The maximum vacuum in the sample chamber is about 10^-3 Torr. The low helium consumption (< 0.12 l/h) enables operation time more than 24 hours. The optCRYO107vac can be used as a nitrogen cryostat on filling liquid nitrogen in helium reservoir.

Operation

Insiide the cryostat body are located the liquid nitrogen and helium reservoirs. The nitrogen bath cools the radiation screen. Liquid He (N2) flows through the capillary into the pre-cooled cylindrical chamber. The heat exchanger is placed in the lower part of the pre-cooled chamber. The cryogenic liquid is evaporated on the heat exchanger and flows upwards. The cryogen gas temperature is regulated by electric power of the heat exchanger. The cylindrical vacuum sample chamber is touched to the heat exchanger of the pre-cooled chamber. The flow rate of the cryogen gas through the pre-cooled chamber is regulated by differential pressure regulator and needle valve controled by electronic unit outside of the cryostat. The combined gas flow and resistive heater temperature regulation results in low consumption of the cooling agent. The temperatures below 4.2 K can be reached by helium vapor pumping. Samples are top loading by the use of the sample holder.

Basic parameters and modifications of optCRYO107vac cryostats

* – Temperature regulation system tSTAT310x is strongly recommended.

Complete system

1. optCRYO107vac cryostat.

2. Temperature controller tSTAT310x with Manostat.

3. Vacuum isolated transfer line.

4. Sample holder.

Optionally

1. Optimization of windows configuration for optical experiments.

2. Maximal number of windows in horizontal plane – 5.

3. Windows material

• Sapphire.

• A2B6 (ZnSe, ZnS, CdTe) and other materials on request.

4. Aperture of an optic window up to 28°.

5. Clear diameter of an optical window up to 20 mm.

6. Windows depolarization ratio less than 1%.

7. Angle between window axes is 45°, 90°, 180°.

8. Height of windows above the cryostat bottom from 80 to 400 mm.

9. Rectangular cryostat tail for experiments in magnetic field. Minimal distance between magnet poles is 65 mm.

10. Calibrated coal temperature sensors.

Additional equipment

1. Sample holder

• Sample rotation by 360° in vertical and horizontal planes.

• X and XY shift of the sample.

• Asymmetric sample position for microscopy.

• Up to 200 kg mechanical stress applied at helium temperatures.

2. He-transfer vacuum isolated line

• Variable length connection.

• Flexible connection.

3. Tubes connections.

4. Sample rod with a universal flange.

5. Measuring heads, cassette heads.

6. Multipin electric connector on the sample holder.

7. Storage helium or nitrogen dewar.

8. Dewar transport platform.

Key benefits

• Low consumption of the cooling agent.

• He and N2 operation modes of the system.

• Competitive price for the system set.